The scientists wanted to know if brand loyalty is purely culturally based, or built into our primate brains. So they showed rhesus monkeys some brand logos—like Pizza Hut and Adidas—next to pictures of high-status, low-status, or sexually presenting monkeys, or next to pictures of random noise. The monkeys could click any logo to get a piece of candy. They were basically making ads for the brands.

And the ads worked. Even after the researchers took out the attractive pictures, the monkeys kept picking the Adidas logo just because they’d seen it next to a sexy monkey ass, and the Acura logo because they’d seen it next to a high-status monkey. They’d never been rewarded for choosing certain logos; every click always delivered the same candy. The scientists built brand loyalty by pure association. Which is exactly what real commercials do.

So commercials work; that’s not news. But it’s interesting that they work at such a basic, primal level. The next time you’re tempted to spring for the “good brand,” ask yourself if you have evidence that the brand is better, or if you’re just being a horny monkey.